In the past, it has generally been found necessary to introduce a true time delay phase shift when operating a large, phase scan antenna at wide angles. This holds true when dealing with both standard and compressed or chirped pulses.
The prior art accepted the bandwidth/scan limitations and used the true time delay scanning mechanism when required by bandwidth/scan angle considerations. Although this approach can be made practical in a receive system, it involves considerable cost and complexity in a transmit system where high power RF signals are present.
A more complete description of electronically scanned antennas in general may be had by referring to texts on the subject, one being a book by Peter J. Kahrilas, entitled "Electronic Scanning Radar Systems Design Handbook" published by Artech House, Inc., Dedham, Mass., 1976.